Okay. Spent a large chunk of the day hacking the last final bits of the NTPCkr web page together and made it available for public viewing. Yippee! There's a link on the front page in the news section if you're looking for it.

There's still a ton more work to be done on this page, as well as the NTPCkr itself, and this is still just the first step in many as far as final data analysis is concerned. We haven't even touched radio frequency interference removal yet (outside of the tools we already have from other SETI projects that we could retrofit for SETI@home). Still, it's a (seemingly rare) major step in the right direction around here.

I also had a code walkthrough with Jeff/Eric about my radar blanking difficulties. Eric had several good things to try, which I'll get started on once I post this message. Actually I might look into the stuck science status page first...

- Matt

____________
-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude

In general, i see that i cannot start a new thread in the NTPCkr forum. But i can reply to the "Candidate" messages. I have read a large amount of science information over the last few weeks but I still have some general questions that are not answered on the FAQ. I'm sure others might want to ask some general questions during the initial learning process with the new NTPCkr.

The theory being that questions can be asked, and maybe you can answer them and they could be added to the FAQ. But i'm not sure, maybe you plan to read all the messages posted in the individual candidate messages so you can answer the most frequent ones in the FAQ.

Matt the NTPCkr is very impressive, its very cool, and thank you for your efforts!

Have you given any thought to a joint venture or research project between SETI@Home and Einstein@Home? Seems like you guys could share "candidates" or at least RFI cleansing code. If a high-ranking candidate has a positive "stars" column, perhaps this should be checked by Einstein@Home clients?

However, I believe it's a serious mistake to make "repeats at the same frequency" a screening criterion. Nearly any plausible transmitter will show frequency drifts due to orbital (i.e. accelerated) motion. For instance, if a large beacon transmitter were broadcasting from an 0.1 a.u. orbit around a sunlike star (to collect lots of solar energy, and to keep the transmitter away from the home planet), it would show a frequency drift back and forth ranging over the *entire* 2.5 MHz bandwidth of SETI@home (rough calculation; also depends on the orbital inclination).

For that matter, a lot of what S@H does is *look* for frequency drifts. A drift of 5 Hz/sec crosses the 2.5 MHz bandwidth in 6 days.

So, I really think you should have a version of NTPCkr running that does not filter out persistent signals because they differ in frequency.

I'd bet higher than 10 to 1 odds that if a signal is ever found, it will show frequency drifts (even after correction to the solar system's barycenter to remove Earth's own motion).

However, I believe it's a serious mistake to make "repeats at the same frequency" a screening criterion. Nearly any plausible transmitter will show frequency drifts due to orbital (i.e. accelerated) motion.

... or just plain drifts in the electronics.

But, at the end of the day, what they have is a great big pile of "signal candidates" that are not very obvious signals. You have to pick some criteria to try to pick the "interesting" from the "uninteresting."

So, they've got the NTPKCR looking for persistent signals.

If that doesn't show results, they still have all of the original results and they can try a "frequency-relaxed" NTPCKR, or some other idea that we haven't thought about.

However, I believe it's a serious mistake to make "repeats at the same frequency" a screening criterion. Nearly any plausible transmitter will show frequency drifts due to orbital (i.e. accelerated) motion. For instance, if a large beacon transmitter were broadcasting from an 0.1 a.u. orbit around a sunlike star (to collect lots of solar energy, and to keep the transmitter away from the home planet), it would show a frequency drift back and forth ranging over the *entire* 2.5 MHz bandwidth of SETI@home (rough calculation; also depends on the orbital inclination).

For that matter, a lot of what S@H does is *look* for frequency drifts. A drift of 5 Hz/sec crosses the 2.5 MHz bandwidth in 6 days.

So, I really think you should have a version of NTPCkr running that does not filter out persistent signals because they differ in frequency.

I'd bet higher than 10 to 1 odds that if a signal is ever found, it will show frequency drifts (even after correction to the solar system's barycenter to remove Earth's own motion).

Alan MacRobert
Senior Editor
Sky & Telescope

Alan,
You have highlighted an interesting point there about frequency drift. In essence i believe the guys writing the algorithms to search for candidates are taking into account as many parameters as they possibly can. But i think you have highlighted just one of many difficulties involved in this type of search.

I really don't envy the task the scientists have in writing this search algorithm code. Its even more difficult with thousands of volunteers creating doubt in your mind about the code you have written. I do believe the guys are trying their best to cover every possibility. I also think the scientists are aware of the catch 22 problem created by the orbit of the earth and the possible orbit of any candidate.

that says we are actually doing work with a slim chance of producing useful results.

Yes, "we." When I clicked on ID's, I was hoping to also see a who's-who of participants & CPUs that did WUs on that sky coordinate (that ultimately NTPCkr stood upon to create it's Greatest Hits list). Or are the worker ants long forgotten at that point?

... and to emphasize the grander point, NTPCkr is very cool, well done Matt.

that says we are actually doing work with a slim chance of producing useful results.

Yes, "we." When I clicked on ID's, I was hoping to also see a who's-who of participants & CPUs that did WUs on that sky coordinate (that ultimately NTPCkr stood upon to create it's Greatest Hits list). Or are the worker ants long forgotten at that point?

The "worker ants" are not lost.

SETI@Home has always said that those who crunched would get credit right along with the researchers actually conducting the science.

I suspect they aren't listed because the NTPCKR results are incredibly preliminary.

We are a Litmus test. Litmus paper will detect the presence of an acid, but it won't give you accurate pH readings.